m_spanningtree Create new TreeServers for incoming connections only when they've accepted our credentials, not when they send SERVER

3 files changed, 60 insertions, 25 deletions

diff --git a/src/modules/m_spanningtree/server.cpp b/src/modules/m_spanningtree/server.cpp
index 33c7f47b3..a04454f51 100644
--- a/src/modules/m_spanningtree/server.cpp
+++ b/src/modules/m_spanningtree/server.cpp
@@ -180,6 +180,33 @@ bool TreeSocket::Outbound_Reply_Server(parameterlist &params)
 	return false;
 }
 
+bool TreeSocket::CheckDuplicate(const std::string& sname, const std::string& sid)
+{
+	/* Check for fully initialized instances of the server by name */
+	TreeServer* CheckDupe = Utils->FindServer(sname);
+	if (CheckDupe)
+	{
+		std::string pname = CheckDupe->GetParent() ? CheckDupe->GetParent()->GetName() : "<ourself>";
+		SendError("Server "+sname+" already exists on server "+pname+"!");
+		ServerInstance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, already exists on server "+pname);
+		return false;
+	}
+
+	/* Check for fully initialized instances of the server by id */
+	ServerInstance->Logs->Log("m_spanningtree",DEBUG,"Looking for dupe SID %s", sid.c_str());
+	CheckDupe = Utils->FindServerID(sid);
+
+	if (CheckDupe)
+	{
+		this->SendError("Server ID "+CheckDupe->GetID()+" already exists on server "+CheckDupe->GetName()+"! You may want to specify the server ID for the server manually with <server:id> so they do not conflict.");
+		ServerInstance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, server ID '"+CheckDupe->GetID()+
+				"' already exists on server "+CheckDupe->GetName());
+		return false;
+	}
+
+	return true;
+}
+
 /*
  * Someone else is attempting to connect to us if this is called. Validate their credentials etc.
  *		-- w
@@ -226,39 +253,24 @@ bool TreeSocket::Inbound_Server(parameterlist &params)
 			continue;
 		}
 
-		/* Now check for fully initialized ServerInstances of the server by name */
-		TreeServer* CheckDupe = Utils->FindServer(sname);
-		if (CheckDupe)
-		{
-			std::string pname = CheckDupe->GetParent() ? CheckDupe->GetParent()->GetName() : "<ourself>";
-			SendError("Server "+sname+" already exists on server "+pname+"!");
-			ServerInstance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, already exists on server "+pname);
+		if (!CheckDuplicate(sname, sid))
 			return false;
-		}
 
-		/* Check for fully initialized instances of the server by id */
-		ServerInstance->Logs->Log("m_spanningtree",DEBUG,"Looking for dupe SID %s", sid.c_str());
-		CheckDupe = Utils->FindServerID(sid);
+		ServerInstance->SNO->WriteToSnoMask('l',"Verified incoming server connection " + linkID + " ("+description+")");
 
-		if (CheckDupe)
-		{
-			this->SendError("Server ID "+CheckDupe->GetID()+" already exists on server "+CheckDupe->GetName()+"! You may want to specify the server ID for the server manually with <server:id> so they do not conflict.");
-			ServerInstance->SNO->WriteToSnoMask('l',"Server connection from \2"+sname+"\2 denied, server ID '"+CheckDupe->GetID()+
-					"' already exists on server "+CheckDupe->GetName());
-			return false;
-		}
+		this->SendCapabilities(2);
 
-		ServerInstance->SNO->WriteToSnoMask('l',"Verified incoming server connection " + linkID + " ("+description+")");
-		linkID = sname;
+		// Save these for later, so when they accept our credentials (indicated by BURST) we remember them
+		this->capab->hidden = x->Hidden;
+		this->capab->sid = sid;
+		this->capab->description = description;
+		this->capab->name = sname;
 
-		// this is good. Send our details: Our server name and description and hopcount of 0,
+		// Send our details: Our server name and description and hopcount of 0,
 		// along with the sendpass from this block.
-		this->SendCapabilities(2);
 		this->WriteLine("SERVER "+ServerInstance->Config->ServerName+" "+this->MakePass(x->SendPass, this->GetTheirChallenge())+" 0 "+ServerInstance->Config->GetSID()+" :"+ServerInstance->Config->ServerDesc);
-		// move to the next state, we are now waiting for THEM.
-		MyRoot = new TreeServer(Utils, sname, description, sid, Utils->TreeRoot, this, x->Hidden);
-		Utils->TreeRoot->AddChild(MyRoot);
 
+		// move to the next state, we are now waiting for THEM.
 		this->LinkState = WAIT_AUTH_2;
 		return true;
 	}
diff --git a/src/modules/m_spanningtree/treesocket.h b/src/modules/m_spanningtree/treesocket.h
index c1ca5e74a..d8445572b 100644
--- a/src/modules/m_spanningtree/treesocket.h
+++ b/src/modules/m_spanningtree/treesocket.h
@@ -78,6 +78,12 @@ struct CapabData
 	int capab_phase;			/* Have sent CAPAB already */
 	bool auth_fingerprint;			/* Did we auth using SSL fingerprint */
 	bool auth_challenge;			/* Did we auth using challenge/response */
+
+	// Data saved from incoming SERVER command, for later use when our credentials have been accepted by the other party
+	std::string description;
+	std::string sid;
+	std::string name;
+	bool hidden;
 };
 
 /** Every SERVER connection inbound or outbound is represented by an object of
@@ -95,6 +101,11 @@ class TreeSocket : public BufferedSocket
 	bool LastPingWasGood;			/* Responded to last ping we sent? */
 	int proto_version;			/* Remote protocol version */
 	bool ConnectionFailureShown; /* Set to true if a connection failure message was shown */
+
+	/** Checks if the given servername and sid are both free
+	 */
+	bool CheckDuplicate(const std::string& servername, const std::string& sid);
+
  public:
 	time_t age;
 
diff --git a/src/modules/m_spanningtree/treesocket2.cpp b/src/modules/m_spanningtree/treesocket2.cpp
index 04ca9edb1..5007fe921 100644
--- a/src/modules/m_spanningtree/treesocket2.cpp
+++ b/src/modules/m_spanningtree/treesocket2.cpp
@@ -164,9 +164,21 @@ void TreeSocket::ProcessLine(std::string &line)
 						ServerInstance->SNO->WriteGlobalSno('l',"\2WARNING\2: Your clocks are out by %d seconds. Please consider synching your clocks.", abs((long)delta));
 					}
 				}
+
+				// Check for duplicate server name/sid again, it's possible that a new
+				// server was introduced while we were waiting for them to send BURST.
+				// (we do not reserve their server name/sid when they send SERVER, we do it now)
+				if (!CheckDuplicate(capab->name, capab->sid))
+					return;
+
 				this->LinkState = CONNECTED;
 				Utils->timeoutlist.erase(this);
 
+				linkID = capab->name;
+
+				MyRoot = new TreeServer(Utils, capab->name, capab->description, capab->sid, Utils->TreeRoot, this, capab->hidden);
+				Utils->TreeRoot->AddChild(MyRoot);
+
 				MyRoot->bursting = true;
 				this->DoBurst(MyRoot);